Sheet binding



Aug. 25, 1970 5, GR|NNELL ET AL 3,525,126

a SHEET BINDING Filed April 1, 1968 2 Sheets-Sheet 1- INVENTORS GEORGEG. GRINNELL SHERMAN K. GRINNELL BY GARITH K. GRINNELL ATTORNEYS Aug. 25,1970 GR|NNELL ETAL 3,525,126

SHEET BINDING Filed April 1, 1968 2 Sheets-Sheet 2 INVENTORS GEORGE G.GRINNELL SHERMAN K. GRINNELL BYGARITH K. GRINNELL ATTORNEYS UnitedStates Patent Office 3,525,126 Patented Aug. 25, 1970 3,525,126 SHEIEEIISIISIDINdG A Q eor e G. Grinnell 6 n epen ence ve., uincy, Mzi ss.02169; Sherman K. Grinnell, 1196 Belrose Road, Mayfield Heights,Cleveland, Ohio 44124; and Garith K. Grinnell, 187 Indianhead St.,Hanson, Mass. 02341 Filed Apr. 1, 1968, Ser. No. 717,738

Int. Cl. B29c 17/00 US. Cl. 1819 3 Claims ABSTRACT OF THE DISCLOSURE Adrilled stack of sheets is bound by plastic that elements are pre-formedinto multi-leg devices by means of a rotating die which sets the heatsoftened element into a finished shape. These are then inserted into thedrilled openings by a spreading mechanism.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates generally to sheet binding and more particularly is directedtowards new and improved sheet binding devices, apparatus for formingthe binding elements and finally apparatus for inserting the bindingelements in the drilled stack.

Description of the prior art In US. patents numbered 2,377,340,2,850,927 and 3,073,355 there are disclosed various portions of a sheetbinding apparatus adapted to form binding elements from wire, drilling apile of sheets to be bound, and inserting the binders through thedrilled holes in the sheets. The apparatus discloses in these patents atthe time represented a substantial advance in the art of sheet bindinginsofar as it is capable of high productivity as well as producing abound volume of improved quality. The present invention has for one ofits objects providing improvements in the sheet binding apparatusdisclosed in the foregoing patents and specifically for providing sheetbinding mechanisms and sheet binding elements capable of producing boundvolumes such as notebooks, check books, paper back books, calendars,loose-leaves or the like at a much higher rate of productivity andproducing bound volumes of superior characteristics and of uniformquality.

SUMMARY OF THE INVENTION This invention features novel binding elementsfor binding a drilled stack of sheets. The elements are preformedone-piece multi-looped devices of plastic. The plastic binding elementsare formed by an apparatus which includes a ramp along which individualelements are fed past a heat source to soften the elements prior todelivery to a rotary die mechanism which forms and sets the elementsinto the desired loops.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation,somewhat schematic, of an apparatus for forming plastic binding elementsaccording to the invention,

FIG. 2 is a view in perspective of a binding element made by the FIG. 1apparatus,

FIG. 3 is a top plan view, partly in section of the forming die of FIG.1,

FIG. 4 is a detail end view of an apparatus for temporarily openingplastic binding elements,

FIG. 5 is a modification thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1, 2 and 3,there is illustrated a binding element of plastic material along withthe ap paratus for making the same. As shown in FIG. 2 a binding elementis formed with an elongated cross-piece 122 from which extends aplurality of substantially closed loops 124 spaced from one another andadapted to be inserted in the drilled openings of a pad of paper. Thebinding element of FIG. 2 is formed by the mechanism illustrated inFIGS. 1 and 3. The mechanism includes an inclined upper chute 126 forstoring a supply of binding elements 120 which at this stage comprisessimply the straight cross-piece 122 and a plurality of straightdepending legs 128 which are to be formed into the loops shown in FIG.2. The binding elements are restrained on the chute 126 by means of anindexing wheel 130 which, upon actuation, is adapted to dispense thebinding elements one-by-one onto an inclined lower chute 132. Bindingelements stored in the upper chute 126 are subjected to a heat sourcedirected through a vent 134, this heat source being at a selectedtemperature which preheats the supply of binding elements indefinitelywithout damage to them. When the indexing wheel 130 is actuated theleading binding element is dispensed onto the lower chute 132 where itslides down and is temporarily stopped by means of a release mechanism136. The release mechanism holds the element 120 below a second andhigher intensity heat source 138 which raises the individual element toa forming temperature. When the element 120 has reached the propertemperature the release mechanism 136 is actuated permitting the element120 to slide down to a forming mechanism 140.

This mechanism includes a die 142 comprised of upper and lower blocks144 and 146 respectively. These blocks are hinged to one another andadapted to be opened and closed automatically on signal by any suitablemeans such as a solenoid or the like. The blocks are formed with ahorizontal cylindrical mandrel 150. The mandrel is formed with alongitudinal groove 152 adapted to receive the cross-piece portion 122of the binding element. As shown in FIG. 1, the binding element isdelivered to the forming mechanism with the cross-piece leading andbeing picked up by the groove in the mandrel which is shown in its startposition in FIG. 1. The cylindrical walls of the die passage are formedwith annular grooves 154 positioned and dimensioned to receive the legsof the binding element. When the binding element is fed into the formingmechanism and its cross-piece 122 received in the mandrel groove, themandrel is rotated as by a motor 156. Rotation of the mandrel serves todraw the binding element into the forming mechanism counterclockwise asviewed in FIG. 1. This will wrap the binding element about the mandrelto form the straight legs into the loops 124. 'Once the binding elementhas been wrapped about the mandrel, it is allowed to set long enough forthe plastic material to stabilize in its new shape. To this end theupper and lower blocks of the die are provided with a cooling system,the cooling medium being pumped through conduits 156 and 158. When thebinding element has fully set, the forming blocks open and a travelingsweep 160 is actuated to slide the finished element off the mandrel. Thesweep preferably is in the form of an elongated arm the end of whichbears against the mandrel and extends right angularly therefrom. Thesweep may be actuated by any suitable means such as a piston andcylinder 162 as illustrated in FIG. 3.

Binding elements made according to the foregoing 3 mechanism may then beinserted in the drilled openings of a pad of paper either manually 'byspreading apart the legs sufficiently to insert them in the openings oran automatic mechanism may be provided to carry out this operation assuggested in FIGS. 4 and 5.

In the FIG. 4 device, the element 120 is held in position by an arm 159that engages the cross-piece 122 while an offset member 161 pivotsagainst the loops 124 to open and close them. In FIG. 5, the element isrestrained by a slide pin 1 63 while a hook-like arm 165 pulls againstthe cross-piece 122 to open the loops. A spring loaded treadle and crankare employed to actuate the arm 165.

Having thus described the invention what We claim and desire to obtainby Letters Patent of the United States 1. Apparatus for forming aplastic binding element having a straight cross-piece and a plurality ofcircular loops from a starting element having a straight crosspiece anda plurality of straight legs extending perpendicularly therefrom,comprising (a) an inclined chute adapted to store a quantity of saidstarting elements,

(b) heating means adjacent said chute for softening said elements,

() feed means for releasing said elements one by one down said chute,

(d) a die located at the end of said chute to receive each of saidelements,

(e) said die being formed with separable portions formed with acylindrical passage and a cylindrical member mounted therein,

(f) the walls of said passage being formed with a plurality of spacedarcuate grooves to receive the legs of said element and the surface ofsaid member being formed with a longitudinal groove to receive saidcross-piece,

(g) :means to rotate said member when said cross-piece is received insaid groove to Wrap said legs about said member and form them intoloops, and,

(h) means to separate said die portions and remove said element aftersaid element has been set.

2. Apparatus according to claim 1 including another heat source prior tosaid first mentioned heat source for pre-heating said elements.

3. Apparatus according to claim 1 including cooling means connected tosaid die.

References Cited UNITED STATES PATENTS 1,514,708 11/1924 Lucas 1819 XR2,211,743 8/1940 Nelson et al. 18--19 2,450,324 9/1948 Wilson et a1.1819 2,676,360 4/1954 Emmer l8-19 XR 2,686,932 8/1954 Zaleski 18-19WILLIAM J. STEPHENSON, Primary Examiner

